Citation and License

Diagnostic Pathology 2011, 6:73
doi:10.1186/1746-1596-6-73

Published: 8 August 2011

Abstract

Background

Cancer stem cell (CSC) hypothesis postulates that tumors are maintained by a self-renewing
CSC population that is also capable of differentiating into non-self-renewing cell
populations that constitute the bulk of tumor. Stem cells renewal and differentiation
can be directly influenced by the oxygen levels of determined tissues, probably by
the reduction of oxidative DNA damage in hypoxic regions, thus leading to a friendlier
microenvironment, regarding to clonal expansion and for resistance to chemotherapeutic
regimens. Furthermore, there have been strong data indicating a pivotal role of hypoxic
niche in cancer stem cells development. There are evidence that hypoxia could drive
the maintenance of CSC, via HIF-1α expression, but it still to be determined whether
hypoxia markers are expressed in breast tumors presenting CD44+CD24-/low immunophenotype.

Methods

Immunohistochemical analysis of CD44+CD24-/low expression and its relationship with hypoxia markers and clinical outcome were evaluated
in 253 samples of breast ductal carcinomas. Double-immunolabeling was performed using
EnVision Doublestain System (Dako, Carpinteria, CA, USA). Slides were then scanned
into high-resolution images using Aperio ScanScope XT and then, visualized in the
software Image Scope (Aperio, Vista, CA, USA).

Conclusion

Considering that there are strong evidences that the fraction of a tumour considered
to be cancer stem cells is plastic depending upon microenvironmental signals, our
findings provide further evidence that hypoxia might be related to the worse prognosis
found in CD44+CD24-/low positive breast tumors.